单项选择题
A.A common rail engine；conventional engines B.A conventional engine；common rail engines C.A marine diesel engine；most other engines D.A two-stroke engine；four-stroke engines
In a common rail engine, the fuel is injected into cyli...
单项选择题In a common rail engine, the fuel is injected into cylinders（）
A.by injection pumps B.at a time decided by the injection pump timing C.by a signal opening the magnetic valves D.at a time decided by the cam directly
In common rail engines, the fuel is（） before is injecte...
单项选择题In common rail engines, the fuel is（） before is injected into the cylinders.
A.stored in a common fuel line B.pumped by the injection pump C.at low pressure D.already atomized
In conventional systems, the injection pressure（）, whil...
单项选择题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.
A.fluctuates with the engine speed to some extent, independent of the engine speed B.keeps constant at all engine speed, dependent on the engine speed to some extent C.keeps constant at all engine speed, independent of the engine speed D.is decided by the engine speed, constant at all engine speed
